FORT WORTH (CBSDFW.COM) – A Grapevine-Colleyville ISD teacher is on administrative leave and the subject of a police investigation.

The school district sent home a letter to Colleyville Heritage High School parents informing them that police are investigating an inappropriate relationship between music teacher Cody Dickson and a student. (Click here to download the letter).

Dickson has been employed at the school since August 2009 and also served as an assistant choir director at the school.

He will be banned from campus pending the outcome of the investigation.